Synthesis and Optoelectronic Properties of Nanocomposites Comprising of Poly(9,9-dioctylfluorene)-Block-Poly(3-hexylthiophene) Block Copolymer and Graphene Nanosheets

Abstract

A novel conjugated block copolymer, poly(9,9-dioctylfluorene)-block-poly(3-hexylthiophene) (PFBPT) and its nanocomposite containing graphene sheets were synthesized for enhancing optoelectronic performance. Graphene sheets were in-situ formed in the polymer matrix via a reduction of octadecylamine-functionalized graphite oxide, where the graphite oxide came from acidification and exfoliation of graphite. The blue-green light-emitting poly(9,9-dioctylfluorene) block and red-orange light-emitting poly(3-hexylthiophene) block exhibit a combined white electroluminescence when the composite materials were fabricated as the emitting layer of a polymeric light-emitting diode (PLED). Graphene does not alter the optical characteristics wavelength of PFBPT but electric conductivity increases with the amount of graphene. The HOMO and LUMO were measured and the band gap is smaller with existence of graphene. The threshold voltage decreases with an increase in the graphene content. The device fabricated with PFBPT/graphene nanocomposite containing 1% graphene has a maximum white-light luminescence at a voltage of 9.0 V.

Effect of graphene oxide size and structure on synthesis and optoelectronic properties of hybrid graphene oxide‐poly(3‐hexylthiophene) nanocomposites

“…Hybrid materials of conducting polymers with two‐dimensional nanofillers have received significant research attention in the past few years . These materials are studied for various applications such as sensors supercapacitors , photovoltaic devices , and so on . Among the conducting polymers, poly(3‐hexylthiophene) (P3HT) is one of the widely investigated semiconducting polymers, partly because the hexyl group is sufficiently long to confer good solubility to the prepared polymer, without diluting the conjugated backbone and possesses excellent stability to weathering and degradation.…”

“…The composite morphology was very uniform, and the carrier mobility of the polymer composites was enhanced by fourfold, whereas the photocurrent was increased by 17% at low loading of GNDs. In another study, the synthesis of conjugated poly(9,9dioctylfluorene)blockpoly(3hexylthiophene) block copolymer, and its nanocomposite containing graphene sheets were reported by Chiu et al for enhanced optoelectronic performance. The electric conductivity increased with the amount of graphene without altering the optical characteristics of the block copolymer.…”